“A discussion of”, “a discussion on”, and “a discussion about”: When is each phrase used in preference to the other?
If context is important, I want to use it as a subheading on a piece of non-fiction.

6 Answers
6

A discussion about a topic — this implies that the discussion was just a conversation, really, and it might not have stayed strictly on-topic.

A discussion of a topic — this brings to mind a true discussion, going into all sorts of details of the topic (and only the topic).

A discussion on a topic — here I picture the discussion to be somewhat one-sided, almost a lecture.

Note that all of these connotations are vague and amorphous, and can be overridden by customary usages, or by what "sounds best" in a given context. If you pressed me to suggest a single best choice, today I'd go with "of". No guarantees about tomorrow.

I partly agree, but the theory doesn't really continue to work if it's "A Discussion of the value of Otters in ...", because then it's clear that the otters were not doing the discussing. I'll have to think about this answer.
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SimonMar 16 '11 at 3:47

@Simon, in that case, i'd rather go with "A discussion on the value of Otters.."
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n0nChunMar 16 '11 at 3:52